These gaskets create a watertight and draught-proof seal between a window or door frame, and it's double-glazed unit or infill panel. Replacing gaskets is quick and easy and requires minimal tools, and doing so can stop water ingress, eliminate draughts and noise, improve energy efficiency, safety and security. 'E' Gaskets get their name from their profile, which can resemble the letter E, and are also referred to as Fir Tree gaskets because they resemble the downward slopping branches of a fir tree. A mushroom extrusion that runs along these gaskets is pushed tightly into a groove in the profile. Then under compression against the double-glazed unit, the branches of the fir tree create multiple seals. Made from a Thermoplastic Elastomers (TPE) material, a blend of plastic and elastic polymer. So they're durable, thermally efficient, with a core of polypropelene (PP), or PVC nitrile, to resist overstretch and expansion. Seals between double-glazed unit and frame Stops water ingress, draughts and noise Durable core strengthens and resists overstretch Long lasting UV stable and weather resistant Fit easily without special tools or adhesive, Weight: 1.8849523401 pounds, Manufacturer: ExtrudaSeal